RF identification reader for communicating condition information associated with the reader

ABSTRACT

A radio frequency identification (RFID) system comprises an RFID tag and an RFID reader that communicates with the tag and a processor. A dynamic electronic product code (EPC) is associated with the reader. The dynamic EPC includes at least one portion that is variable.

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of U.S. ProvisionalApplication Serial No. 60/426,927, filed Nov. 15, 2002, entitled“Methods and Apparatus for Communicating Condition InformationAssociated With an Item,” and further claims the benefit of U.S.Provisional Application Serial No. 60/475,554, filed Jun. 3, 2003,entitled “Methods and Apparatus for Communicating Condition InformationAssociated With an Item.” The entire disclosure of each of theaforementioned applications is hereby incorporated herein by reference.

FIELD OF INVENTION

[0002] The present invention relates generally to methods and apparatusfor communicating information relating to one or more detectibleconditions associated with an item. More particularly, one embodiment ofthe present invention is directed to a radio frequency (RF)identification system that employs dynamic electronic product codes(EPCs) having a variable content and/or length to represent informationrelating to one or more conditions associated with an item.

BACKGROUND

[0003] Auto-ID technology relates generally to using the Internet totrack goods in a manufacturing process and/or supply chain (e.g. frommanufacturer to distributor to point of sale location). One contemplatedinfrastructure for implementing the Auto-ID technology to transportinformation relating to physical objects via the Internet includes fourmajor components: 1) electronic tags; 2) an electronic product code(EPC); 3) an object naming service (ONS); and 4) a physical markuplanguage (PML).

[0004] An electronic tag typically is in the form of a small chip thatis affixed to or otherwise integrated with an item to be tracked. Suchtags may be implemented using a family of technologies that facilitatethe transfer of data wirelessly between tagged objects or items andelectronic readers. For example, radio frequency identification (RFID)tags have small radio antennas which are capable of transmitting dataover a short range. Such RFID tags, when coupled to an RF readernetwork, facilitate tracking and identification of tagged items fromplace to place throughout all or a portion of a manufacturing process orsupply chain/distribution network.

[0005] To uniquely identify tagged objects, a naming system referred toas the electronic product code (EPC) has been developed. The EPC wascreated to accommodate current and future naming methods, and isintended to be universally and globally accepted as a means to linkphysical objects to a computer network and to serve as an efficientinformation reference. A unique EPC assigned to an item to be trackedtypically is “burned” into a memory/storage device of an RFID tag as afixed binary number. Currently, EPCs typically are either 64 or 96 bitslong. The EPC bit string is intended to uniquely identify an item byencoding the manufacturer, the product type, and the product serialnumber, for example.

[0006] It should be appreciated that the EPC in the RFID tag does notchange as the item to which the tag is affixed goes through amanufacturing process and/or a supply chain; in particular, the RFID tagis designed to send a representation of the EPC as a fixed length andfixed content “information payload” to an RF reader or receiver. Whenqueried (i.e., when passing an RF reader), the RFID tag wirelesslytransmits a representation of the EPC to the reader, which in turnpasses the received information on to one or more other processingdevices for decoding the received information and subsequent routing. Inthe current art, components such as the savant, on object naming service(ONS) and PML server decode the tag.

[0007] The object naming service (ONS) is the “glue”, which links theelectronic product code (EPC) with one or more associated data filescontaining information relating to the tagged item. More specifically,the ONS is an automated networking service which, when given an EPC,returns one or more network addresses at which one or more data filescorresponding to the tagged item may be located. In a typical systemconfiguration, the ONS may be accessed by a computer that is local tothe RF reader (and which provides user access to the system). The ONS isbased on the concept of the standard domain naming service (DNS) used toidentify website addresses corresponding to website names. For example,in a manner similar to that employed by the DNS, the ONS parses the EPCto decode particular information in specific fields of the EPC (e.g.,the manufacturer ID, as shown in FIG. 1) so as to return (e.g., to aprocessor local to the RF reader) the appropriate address(es) where datais located.

[0008] The physical markup language (PML) is a standardized languageprotocol in which network information about physical objects is written.PML essentially is an XML-based language for databasing informationabout physical objects, and is designed to standardize descriptions ofphysical objects for use by both humans and machines. In one aspect, PMLserves as a common base for software applications, data storage andanalytical tools for industry and commerce. Once the ONS decodes an EPCas discussed above, it returns (e.g., to a local processor) one or moreaddress(es) to a PML server which includes one or more databases inwhich are stored one or more files containing information regarding thetagged item. The local processor then may forward all or part of the EPCto the PML server, which in turn further processes the EPC to access theinformation in the database(s) regarding the tagged item. The PML serverprovides a standardized data output of the information using PML, whichtypically is forwarded back to the location of the RF reader (e.g., thelocal processor) for user analysis.

[0009] Additional details of the Auto-ID technology may be found in thefollowing disclosures, each of which is hereby incorporated herein byreference:

[0010] “The Electronic Product Code (EPC), A Naming Scheme for PhysicalObjects,” David L. Brock, MIT Auto-ID Center White Paper, MassachusettsInstitute of Technology, 77 Massachusetts Avenue, Building 3, 449GCambridge, Mass. 02139-4307, published Jan. 1, 2001;

[0011] “The Compact Electronic Product Code, a 64-bit Representation ofthe Electronic Product Code,” David L. Brock, MIT Auto-ID Center WhitePaper, Massachusetts Institute of Technology, 77 Massachusetts Avenue,Building 3, 449G, Cambridge, Mass. 02139-4307, published Nov. 1, 2001;

[0012] “The Virtual Electronic Product Code,” David L. Brock, MITAuto-ID Center White Paper, Massachusetts Institute of Technology, 77Massachusetts Avenue, Building 3, 449G, Cambridge, Mass. 02139-4307,published Feb. 1, 2002;

[0013] “The Object Name Service, Version 0.5 (Beta),” Oat Systems andMIT Auto-ID Center White Paper, Massachusetts Institute of Technology,77 Massachusetts Avenue, Building 3, 449G, Cambridge, Mass. 02139-4307,published Feb. 1, 2002;

[0014] “The Savant, Version 0.1 (Alpha),” Oat Systems and MIT Auto-IDCenter White Paper, Massachusetts Institute of Technology, 77Massachusetts Avenue, Building 3, 449G, Cambridge, Mass. 02139-4307,published Feb. 1, 2002; and

[0015] “On the design A Global Unique Identification Scheme,” Daniel W.Engels, MIT Auto-ID Center, Massachusetts Institute of Technology, 77Massachusetts Avenue, Building 3, 449G, Cambridge, Mass. 02139-4307,published Jun. 1, 2002.

SUMMARY OF INVENTION

[0016] A radio frequency identification (RFID) system comprises an RFIDtag and an RFID reader that communicates with the tag and a processor. Adynamic electronic product code (EPC) is associated with the reader. Thedynamic EPC includes at least one portion that is variable.

DESCRIPTION OF INVENTION

[0017] One embodiment of the present invention extends the concept of afixed electronic product code (EPC) to allow it to convey informationrelating to one or more conditions associated with an item. FIG. 1illustrates one example of a dynamic EPC according to this embodiment.As shown in FIG. 1, in addition to manufacturer or source information,product type, product serial number, etc., the dynamic EPC may include avariable portion that is dynamically updated (e.g., by a processor in anRFID tag) to include information relating to one or more conditionsassociated with an item. That variable portion could be any one or moreof the manufacturer/source, product type or serial number fields. Asshown in FIG. 1, it is the serial number field that is variable.According to various aspects, this variable portion may be updatedessentially in real time, periodically at some predetermined interval,upon the occurrence of a particular event (e.g., one or more conditionsexceeding a predetermined threshold), and/or when the RFID tag storingthe EPC is queried by an RF reader. Hence, in various aspects of thisembodiment, the EPC may change depending on one or more conditionsassociated with an item or its environment. While the dynamic EPCembodiment shown in FIG. 1 includes separate fields formanufacturer/source ID and product type, the dynamic EPC alternativelymay combine the manufacturer/source ID and product type into a singlefield, referred to as a global trade identification number (GTIN).

[0018] In addition, it should be appreciated that the invention ofmaking variable and dynamic a portion of a field or fields of an EPCcould apply to any now known or later accepted EPCs. For examples, EPCsunder consideration now including fields having location, vehicleidentification numbers (VINs), other product identification numbers, orthe like, could employ the dynamic EPC concept of the invention. One ormore of such fields could include a portion that is variable and dynamicin order to indicate a change in state or condition.

[0019] In another embodiment of the invention, such dynamic EPCs may beprocessed with the same reader and network infrastructure as that usedfor existing RFID tags (e.g. configured for use with static EPCs). Inparticular, as discussed above, like a static EPC, a dynamic EPC may beparsed in a manner similar to that conventionally employed for Internetwebsite addresses (i.e. using an incremental/hierarchal parsing). Forexample, an ONS may decode a particular field of the dynamic EPCassociated with a manufacturer or source ID, and return an address to aPML server for further processing of the dynamic EPC. At the PML server,one or more other fields of the EPC may be decoded, which may provideinformation to the PML server as to how to subsequently decode one ormore remaining fields of the dynamic EPC. These remaining fields mayhave variable length and/or content. For example, with reference againto FIG. 1, the PML server may look to the serial no. field of an EPC todetermine the manner in which to parse/decode/interpret one or moresubsequent fields containing information regarding the condition of theitem or otherwise associated with the item.

[0020] The information encoded in the dynamic EPC regarding one or moreconditions associated with the item may be used for overall qualityassessment of an item, based on such factors including, but not limitedto, temperature monitoring of a perishable product, weight monitoring,shock monitoring, remaining shelf life prediction, and time out ofrefrigeration indications, for example. More generally, the informationencoded in a dynamic EPC according to various embodiments of the presentinvention may relate to any one or more aspects or characteristics of anitem itself, including elements of an item's history, environment,geographic location, and the like. In various aspects of the presentinvention, the implementation of dynamic EPCs particularly facilitatesmonitoring of conditions of perishable products, products for human oranimal consumption or use, agricultural products, medical products (e.g.medicines, vaccines, etc.) as well as other products as they travelthrough manufacturing and supply/distribution chains.

[0021] An overall system for processing such dynamic EPCs is shown inFIG. 2. As shown in FIG. 2, a tag processor of an RFID tag mayperiodically monitor one or more sensors to obtain information relatingto a condition associated with the item. In various embodiments, one ormore sensors may be built in with the tag itself. The tag processor maybe configured to use this information to determine if any alarmconditions have been triggered. If so, the tag processor may modify oneor more appropriate bits in the EPC stored in memory to indicate that analarm condition has occurred. For example, the tag processor may usesensor values to update any counters that are represented in one or morebits of the EPC so as to indicate time out of refrigeration, triplength, etc.

[0022] More generally, various examples of information that may beencoded in a dynamic EPC as “raw” data or as information that has beengenerated by a tag processor based on one or more measured conditionsincludes, but is not limited to, temperature-related information (e.g.,actual temperature, average temperature, mean kinetic temperature, timeabove or below a particular temperature or temperature range or within aparticular temperature range), elapsed time since some event (e.g., tagactivated, by a user or by an RF reader for example, to indicate thebeginning of a monitoring period), weight-related information,geography/location-related information, information relating to physicalconditions (e.g., impact/shock/deformation, etc.), information relatingto a container/package in which an item is stored (e.g., wascontainer/package opened at some point, where, for how long, etc.), aswell as various alarm indications relating to any one or more of theforegoing or other factors associated with an item. From the foregoing,it should be appreciated that a tag processor of an RFID tag configuredto support a dynamic EPC may perform a number of processing functionsrelating to one or more pieces of raw/measured/sensed data to generateinformation that ultimately is represented in some form in a dynamicEPC. It should also be appreciated that the foregoing examples areprovided primarily for purposes of illustration, and that the inventionis not limited in these respects.

[0023] Turning again to FIG. 2, according to one embodiment of theinvention, when the dynamic EPC RFID tag enters an RFID reader's field,the reader transmits a signal to the tag requesting its EPC. The RFinterface in the tag reads the current value of the EPC and transmits itto the reader. The reader receives the tag's transmission and passes theEPC to a local processor. The local processor in turn queries an ONSresolver for the Internet IP address of the PML server storing datarelating to the item represented by the dynamic EPC. For example, asdiscussed above, the ONS resolver decodes a portion of the dynamic EPC(e.g. the manufacturer ID), uses it to determine the IP address of theappropriate PML server, and passes this IP address back to the localprocessor, which then sends the dynamic EPC to the PML server.

[0024] In addition to the foregoing, the local processor also may passto the PML server some information regarding the RF reader that receivedthe EPC; for example, in one embodiment, the RF reader may be associatedwith some form of identification that the local processor passes on tothe PML server. This identification may be a serial no. or someindication of a geographic location of the RF reader, for example. Inone aspect, the RF reader identification may itself be in the form of astatic or dynamic EPC; in the case of a dynamic EPC, informationregarding the status/operating condition of the RF reader itself may beconveyed in addition to or in place of identification/geographiclocation information relating to the RF reader.

[0025] In the case of a dynamic EPC for the reader, a portion of a fieldor fields of that dynamic reader EPC would be variable. That portionwould contain information, that can be dynamically changed, to indicatea change in state of the reader itself. Additionally, informationregarding the version of software or firmware running on the RF readermay be conveyed in the RF reader identification. In this manner, itshould be appreciated that according to one embodiment, the localprocessor may provide to the PML server a first dynamic EPC relating toan item, accompanied by additional information, for example a seconddynamic EPC, relating to the RF reader that acquired the first dynamicEPC.

[0026] Alternatively to the embodiment described, a dynamic EPC would beassociated only with the reader and would indicate a state of thereader. In such an altenate embodiment, the system including the readerwith which the dynamic EPC is associated, may or may not include a tag.If the system does not include a tag, then the dynamic EPC may monitorthe state of the reader.

[0027] Upon receiving a communication from the local processor, the PMLserver in turn decodes the dynamic EPC relating to the item to determinethe tag identification and information associated with the item (e.g.,condition information) to which the tag is affixed. The dynamic EPC PMLserver also may store the current date and time, the tag identification,and the condition information in a database for later reporting andanalysis. If the local processor also provides to the PML server someinformation (e.g., an identifier, static or dynamic EPC, etc.) regardingthe RF reader, the PML server similarly may store this information.

[0028] The PML server then passes back to the local processor an XMLpackage which includes the item ID and the information associated withthe item and/or its environment (including the RF reader if suchinformation is provided) based on the dynamic EPC. The local processorcauses the information either to be displayed (e.g., to an operator) orrelayed to another computer for further processing.

[0029] As shown in FIG. 2, one or both of the ONS resolver and the PMLserver may be located at various locations with respect to the RFIDreader and local processor.

[0030] It should be appreciated that various aspects of the invention,as discussed above, may be implemented in any of numerous ways, as theinvention is not limited to any particular manner of implementation.Examples of specific implementations are provided herein forillustrative purposes only.

[0031] For example, it should be appreciated that in other embodimentsof the invention, the concept of a dynamic EPC is extended to a moregeneral item identifier having at least one portion that has a variablecontent and or length based on one or more conditions associated with anitem. In particular, in one embodiment, the intelligence for monitoringone or more sensed raw conditions (e.g., temperature, time, location,other environmental conditions, etc.), processing the sensed conditions,and modifying a dynamic identifier based on such processing isself-contained in an identification tag to be affixed, attached,integrated or otherwise associated with an item. Additionally, in otherembodiments such dynamic identifiers may be communicated from theidentification tag using techniques other than RF.

[0032] Additionally, it should be appreciated that such identificationtags may be associated with a wide variety of items, examples of whichinclude, but are not limited to, single goods, collections of goods(e.g., a palette of goods), containers for one or more goods (e.g., ashipping container), a vehicle, a person, etc. Also, examples of varioustypes of conditions that may be sensed and processed by such tags andencoded in dynamic identifiers include, but are not limited to, variousenvironmental conditions including temperature and humidity, geographiclocation, pressure (e.g., shock or impact), time, motion, speed,orientation, illumination conditions, and the like. Moreover, one ormore processors integrated with such identification tags may beconfigured to monitor raw conditions and provide information encoded indynamic identifiers based on a predetermined threshold being exceeded byone or more monitored conditions.

[0033] Based on the more general concepts outlined above, a wide varietyof applications for dynamic identifiers are contemplated according tovarious aspects of the present invention. For example, in oneembodiment, a food item such as a bottle of milk may include a tagconfigured with a dynamic identifier that is capable of indicating ifthe milk was exposed to an undesirable temperature condition. In oneaspect of this embodiment, as the tag attached to the bottle of milk isscanned, for example, at a check-out counter, a local processor at thecheck-out counter is able to indicate, based on the scanned identifier,if the milk was exposed to the undesirable temperature condition andperhaps of an inferior quality as a result. In yet another embodiment,an electronic registry sticker having a variable color display may beequipped with a tag including a dynamic identifier that is capable ofindicating an elapsed time from a certain date. In one aspect of thisembodiment, a counter may be implemented to change one or more bits of adynamic identifier to indicate the passage of particular periods oftime. For example, the registry sticker may be configured such that aprocessor integrated with the sticker periodically monitors the dynamicidentifier and turns the sticker yellow when the dynamic identifierindicates that eleven months have passed, and red when the dynamicidentifier indicates that twelve months have passed (e.g., to indicatean expiration of the sticker).

[0034] According to yet another embodiment of the invention, a dynamicidentifier (such as a dynamic EPC) may be varied based on changingconditions in an overall supply/distribution chain. In particular, invarious applications, a dynamic identifier may be varied to indicate alate shipment, an early shipment or a duplicate shipment.

[0035] For example, in one scenario, one box of goods is ordered from asupplier, and two boxes of identical goods inadvertently are shipped bythe supplier. Each box is equipped with a tag including a dynamicidentifier. The first box is received and accepted. The second box isreceived at a later time (e.g., the next day), and the receiver realizesthat it is a duplicate. The tag is configured such that, at this point,the receiver can program the dynamic identifier to indicate that thereceiver is now the shipper, and the original shipper is now thereceiver, so that the duplicate box may be transported back to its placeof origin. In yet another scenario, a box of goods arrives to adestination ahead of schedule, and a tag attached to the goods,including a dynamic identifier, is programmed such that the dynamicidentifier may indicate at a later time period (e.g., three days, threeweeks, etc.) that the early arrival should be placed back into thestream of goods in the supply chain.

[0036] It should be appreciated the foregoing examples are providedprimarily for purposes of illustration, and that all combinations of theforegoing concepts are contemplated as being part of the inventivesubject matter disclosed herein. In particular, all combinations ofclaimed subject matter appearing at the end of this disclosure arecontemplated as being part of the inventive subject matter.

[0037] Having thus described several illustrative embodiments of theinvention, various alterations, modifications, and improvements willreadily occur to those skilled in the art. Such alterations,modifications, and improvements are intended to be within the spirit andscope of the invention. Accordingly, the foregoing description is by wayof example only, and is not intended as limiting. It should beappreciated that while not described herein, the invention contemplatescovering a tag which has an EPC that identifies the tag but also hasadditional memory for storing additional information. This isalternative to the 64-bit or 96-bit embodiments described.

What is claimed is:
 1. A radio frequency identification (RFID) systemcomprising: an RFID tag; and an RFID reader that communicates with thetag and a processor; wherein a dynamic electronic product code (EPC) isassociated with the reader, the dynamic EPC including at least oneportion that is variable.
 2. The system of claim 1, wherein the variableportion of the dynamic EPC can dynamically change and represents adetected state of the reader.
 3. The system of claim 2, wherein thestate includes a status or operating condition of the reader.
 4. A radiofrequency identification (RFID) reader configured to transmit at leastone dynamic electronic product code (EPC) associated with the reader,the at least one dynamic EPC including at least one portion that isvariable and which represents at least one detectable conditionassociated with the reader.
 5. The reader of claim 4, wherein thecondition includes one of a status and operating condition of thereader.